Switch-lock



M. GRUNNET.

SWITCH LOCK.

APPLICATION FILED FEB. 4, 1919.

Patented Aug. 12, 1919.

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UNITED STATES PATENT OFFICE.

MARTIN GRUNNET, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALF T0 HUGO SEILS,

OF CHICAGO, ILLINOIS;

SWITCH-LOCK.

Specification of Letters Patent.

Patented Aug. 12, 1919.

Application filed February 4, 1919. Serial No. 274,948.

To all whom it may concern:

Be it known that I, MARTIN GRUNNET, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Switch-Locks, of which the following is a specification. L

This invention relates to safety devices, particularly to looks for electric switches, and has for its object the provision of a locking device adapted for association with an electric switch of the knife type and operable to engage the handle of the switch for holding the switch in open position, means being provided for engagement by a padlock whereby the device will be securely held in its active position so that the switch cannot be thrown by an unauthorized person.

An important object is the provision of a locking device of this character which may be readily associated with any ordinary existing knife switch without making any alterations in the switch structure, and which may be manufactured as a distinct and separate article.

A further object is the provision of a device of this character which will be extremely simple and inexpensive in manufacture, highly efficient and durable in use and a general improvement in the art.

With the above and other objects and advantages in view, the invention consists in the details of construction to be hereinafter more fully described and claimed, and illustrated in the accompanying drawings, in which:

Figure 1 is a side elevation of the device engaged by a switch and in locked position;

Fig. 2 is a similar view showing the device in open position, and

Fig. 3 is a cross sectional view on the line 3-3 of Fig. 1.

Referring more particularly to the drawings, I have shown a switch of the knife type including the usual supporting base of panel A, a contact post B extending from the base and having pivotally connected therewith the blade G engageable with another contact member D. The blade C is provided with the usual handle E.

.7 whereby the device may be secured upon 'an arcuate slot 11 engaging upon the pin 9,

theends of this slot servin as stops to limit the swinging movement of the plate 10. At its end opposite the slotted end the plate 10 is provided with a shoulder 12 and is-also provided with a hole 13 adapted to be brought into registration with a pair of holes 14 formed in the plates 5 and adapted for engagement by a padlock 15.

In use, the device is positioned upon the base A in alinement with the contacts B and E and in such position that the plate 10 may engage the handle E of the switch. In the operation of the device, the switch blade C is moved to its open position as shown in Fig. 1, after which the plate 10 is moved upon its pivot 8 so that the shoulder 12 will engage against the base of the handle E. The hole 13 will then register with the holes 14 and the padlock 15 is then inserted through them. The swinging movement of the plate 10 from looking to releasing position is limited by engagement of the ends of the slot 11 with the transverse pin 9.

From the foregoing description and a study of the drawing it will be apparent that I have thus provided an extremely simple and eflicient device by means of which an electric switch of the knife type may be securely locked in open position so as to prevent any possible closing of the switch, the use of the device being particularly desirable in case workmen are repairing or otherwise working upon the line.

While I have shown and described the preferred embodiment of the invention, it will of course be readily understood that I reserve the right to make such changes in the form, construction and arrangement of parts as will not depart from the spirit of the invention nor the scope of the subjoined claim.

Having thus described my invention, I claim In combination with an electric knife switch including spaced plates connected by a cross bar provided with a handle, a looking device comprising a supporting bracket including a pair of spaced plates arranged in planes parallel with the blades of the switch, a locking plate pivoted between said spaced plates and having one end provided with an arcuate slot and having its other end formed with a projection providing a shoulder, a guide pin extending transversely across said spaced plates and engaged within said slot, said locking plate being normally in a position with said projection disposed between the spaced plates in non-obstructing position with relation to the cross bar of the said switch when the switch is in one position whereby upon movement of said switch with its cross bar passing along the edge of the supporting bracket the cross bar will engage the other end of the locking plate and cause swinging thereof to bring said shoulder behind said cross bar whereby to prevent movement of the switch in the other direction, and means for locking said locking plate against movement with respect to said spaced plates.

In testimony whereof I afiiX my signature.

MARTIN GRUNNET.

Copies of this patent inay be obtained for hire cents each, by addressing the Commissioner of Patents.

Washington, D. G. 

